3D biomimetic tongue-emulating surfaces for tribological applications

Oral friction on the tongue surface plays a pivotal role in mechanics of food transport, speech, sensing and hedonic responses. The highly specialized biophysical features of human tongue such as micro-papillae-dense topology, optimum wettability and deformability present architectural challenges in designing artificial tongue surfaces, and absence of such biomimetic surface impedes fundamental understanding of tongue-food/ fluid interaction. Herein, we fabricate for the first time, a 3D soft biomimetic surface that replicates the topography and wettability of a real human tongue. The 3D-printed fabrication contains a Poisson point process-based (random) papillae distribution, and is employed to micro-mould soft silicone surfaces with wettability modifications. We demonstrate the unprecedented capability of these surfaces to replicate the theoretically-defined and simulated collision probability of papillae, and to closely resemble the tribological performances of human tongue masks. These de novo biomimetic surfaces pave the way for accurate quantification of mechanical interactions in the soft oral mucosa.